Field of the Invention
The present invention relates to a method for producing an article having a cavity.
Brief Description of the Related Art
Precision casting is commonly used to produce castings which have complex hollow interiors. Examples of such cast articles are valve seat inserts for the piston engine which are provided with an internal cooling channel. In order to produce a hollow interior in the cast article, the casting mould must be provided with the core, which is removed from the article after the solidification of the casting material. Especially in precision casting long holes or channels are difficult to make because the existing core materials are either giving poor surface quality or are difficult to remove from the solidified cast article. For example, the core may be removable with acids or other chemical solutions. This increases the costs of the process and chemical substances have their own disadvantages in storage, handling and disposal. Similar core problems exist with other casting methods and isostatic pressing processes.
Document EP 210027 discloses a method for forming a cast article by slip casting through casting a slip into a casting mould. composed mainly of gypsum and removing of the casting mould after solidification of the slip.